Principal Chief Chad Smith has indicated he will sign the measure, which was approved by the council Monday night.
The change to tribal marriage law would not affect Kathy Reynolds and Dawn McKinley, who were married last month in a Cherokee ceremony. Cherokee Nation laws are not retroactive.
A Cherokee Nation District Court has scheduled a hearing Friday to discuss a legal protest of McKinley's and Reynolds' marriage application. The outcome of that hearing will determine whether their union is legal.
After McKinley and Reynolds applied for the application May 13, Darrell Dowty, chief justice of the Judicial Appeals Tribunal, ordered a moratorium on marriages that was set to expire Monday.
"If we don't address this, we'll have a flood of same-sex marriages," O'Leary said. "This will be a black eye on the Cherokee Nation. Even the state of Oklahoma doesn't allow same-sex marriage."
The state of Oklahoma does not recognize marriages for same-sex couples but does honor marriages recorded by the Cherokees. The tribe handles only a few marriages a year.
State voters will decide in November whether to amend the constitution to strengthen the ban on gay marriage.
